Numerous ultrasound diagnostic apparatuses have been developed in the past that generate ultrasound tomographic images of the interior of a specimen by utilizing ultrasonic waves output from an ultrasonic probe. In addition, such ultrasound diagnostic apparatuses employ technologies for acquiring pressure data generated on the surface of the interior of a specimen. For example, according to the technology described in Patent Document 1, pressure applied to a specimen is calculated from the movement distance of an ultrasonic probe and the contact surface area of the specimen. In addition, according to the technology described in Patent Document 2, the modulus of elasticity of an area of the interior of a specimen is calculated from variations in that area and separately measured blood pressure.    [Patent Document 1] Japanese Patent Application Laid-open No. 2004-089362    [Patent Document 2] Japanese Patent Application Laid-open No. 2001-292995
The technology described in Patent Document 1 does not involve direct measurement of pressure applied to an ultrasonic probe, but rather calculates pressure from other indicators. In addition, the technology described in Patent Document 2 measured blood pressure with a blood pressure measuring unit separately and independently from an ultrasonic probe. Namely, the prior art does not involve direct measurement of pressure on the surface of an ultrasonic probe, but rather that pressure is obtained by an indirect method, thereby resulting in problems with reliability.